原始 URL.createObjectURL 正在产生 UUID. 您可以利用此。

function uuid() {
  const url = URL.createObjectURL(new Blob())
  const [id] = url.toString().split('/').reverse()
  URL.revokeObjectURL(url)
  return id
}

最简单的功能来做到这一点:

function createGuid(){  
   let S4 = () => Math.floor((1+Math.random())*0x10000).toString(16).substring(1); 
   let guid = `${S4()}${S4()}-${S4()}-${S4()}-${S4()}-${S4()}${S4()}${S4()}`;
   
   return guid.toLowerCase();  
}

因此,注意到这篇文章有超过30个答案,这里是...... 这篇文章有:一个“TL;DR”代码部分w/自含的es6类 Xuid一个使用案例和动机讨论部分关于es6类 Xuid提供代码。

class Xuid {
  //@ edges.sm.st, ess.dev: MIT license Smallscript/David Simmons 2020
  //! Can't use `static const field = const` xbrowser (thus, const's duped)
  static get v4New() {
    const ns7Now = this.ns7Now, xnode48 = this.xnode48; let clock_seq13
    // monotonic `clock_seq` guarantee (13-bits/time-quantum)
    if(ns7Now <= this.ns7Now_prevSeq && this.ns7Now_prevSeq)
      clock_seq13 = ((this.ns7Now_prevSeq += 1n) - ns7Now) & 0b1_1111_1111_1111n
    else
      clock_seq13 = 0n, this.ns7Now_prevSeq = ns7Now
    const time60 = ((ns7Now << 4n) & 0xFFFF_FFFF_FFFF_0000n) |
                           (ns7Now & 0x0000_0000_0000_0FFFn),
              v4 = 0x1_00000000_0000_0000_0000_000000000000n |
      (time60 << 64n) | (0x00000000_0000_4000_0000_000000000000n) | // M: V4
      (0b110n << 61n) | (clock_seq13 << 48n) | // N: Variant-2 time-seq collation
      xnode48, s = v4.toString(16)//.substr(1)
    return `{${s.substr(1,8)}-${s.substr(9,4)}-${s.substr(13,4)}-${
      s.substr(17,4)}-${s.substr(21,12)}}`
  }
  static get xnode48()/*:<BigInt#48>*/{
    if(this.xnode48_) return this.xnode48_
    let clockSeqNode; if(typeof URL !== 'undefined' && URL.createObjectURL) {
      const url = URL.createObjectURL(new Blob())
      const id = (url.toString().split('/').reverse()[0]).split('-')
      URL.revokeObjectURL(url)
      clockSeqNode = BigInt('0x'+id[3]+id[4])
    }
    else {
      const a4 = this.a4; this.getRandomValues(this.a4);
      clockSeqNode = (BigInt(a4[2]) << 32n) | BigInt(a4[3])
    }
    // simulate the 48-bit node-id and 13-bit clock-seq
    // to combine with 3-bit uuid-variant
    return this.xnode48_ = clockSeqNode & 0xFFFF_FFFF_FFFFn;
  }
  static get jdNow()/*:<double#ns7>*/{
    // return 2440587.5+Date.now()/864e5 // <- Date-quantum-ms form (7ns form below)
    return this.jdFromNs7(this.ns7Now)
  }
  static get ns7Now()/*:<BigInt#60>*/{
    if(typeof performance !== 'undefined' && performance.now)
      Reflect.defineProperty(this, 'ns7Now',
        Reflect.getOwnPropertyDescriptor(this,'ns7Now_performance'))
    else
      Reflect.defineProperty(this, 'ns7Now',
        Reflect.getOwnPropertyDescriptor(this, 'ns7Now_Date'))
    return this.ns7Now
  }
  static get ns7Now_Date()/*:<BigInt#60>*/{
    // const epoch1582Ns7_bias = 0x1b2_1dd2_1381_4000  // V1 1582 Oct 15
    // const epoch1601Ns7_bias = 0x19d_b1de_d53e_8000n // FILETIME base
    const epoch1970Ns7 = BigInt(Date.now() * 1000_0.0)
    return epoch1970Ns7 + 0x1b2_1dd2_1381_4000n
  }
  static get ns7Now_performance()/*:<BigInt#60>*/{
    const epochPgNs7 = BigInt(performance.now()*/*15*/1000_0.0|/*17*/0)
    if(!this.epoch1970PgNs7) // performance.timing.navigationStart
      this.epoch1970PgNs7 = this.ns7Now_Date - epochPgNs7
    return epochPgNs7 + this.epoch1970PgNs7
  }
  static dateFromJd(jd) {return new Date((jd - 2440587.5) * 864e5)}
  static dateFromNs7(ns7) {
    return new Date(Number(ns7 - 0x1b2_1dd2_1381_4000n) / 1000_0.0)}
  static jdFromNs7(ns7) {   // atomic-clock leap-seconds (ignored)
    return 2440587.5 + (Number(ns7 - 0x1b2_1dd2_1381_4000n) / 864e9)
  }
  static ns7FromJd(jd) {
    return BigInt((jd - 2440587.5) * 864e9) + 0x1b2_1dd2_1381_4000n
  }
  static getRandomValues(va/*:<Uint32Array>*/) {
    if(typeof crypto !== 'undefined' && crypto.getRandomValues)
      crypto.getRandomValues(va)
    else for(let i = 0, n = va.length; i < n; i += 1)
      va[i] = Math.random() * 0x1_0000_0000 >>> 0
  }
  static get a4() {return this.a4_ || (this.a4_ = new Uint32Array(4))}
  static ntohl(v)/*:<BigInt>*/{
    let r = '0x', sign = 1n, s = BigInt(v).toString(16)
    if(s[0] == '-') s = s.substr(1), sign = -1n
    for(let i = s.length; i > 0; i -= 2)
      r += (i == 1) ? ('0' + s[i-1]) : s[i-2] + s[i-1]
    return sign*BigInt(r)
  }
  static ntohl32(v)/*:<Number>*/{return Number(this.ntohl(v))}
}

总结

雖然有,但我希望這對現在有足夠的解釋;試試。

在GitHub上发布 EdgeS Web-Client Eswc 图书馆的一部分时, indexedDb 使用模式与 efs 将作为其设计意图的示例,其中包括处理效率和可用性与 indexedDb 和相关 PWA 同步和复制场景。

朱利安日计算在JavaScript中

基准评分 Novids/sec

const start = Xuid.ns7Now
for(let i = 100000; i; i -=1)
  Xuid.v4New
const end = Xuid.ns7Now
console.log(`Delta 7ns: ${(end-start)/100000n}`)

基于布罗法的答案,我有自己的答案:

这里是使用 crypto.getRandomValues 的加密更强的版本。

函数 uuidv4() { const a = crypto.getRandomValues(新 Uint16Array(8)); let i = 0; return '00-0-4-1-000'.replace(/[^-]/g, s => (a[i++] + s * 0x10000 >> s).toString(16).padStart(4, '0') ); } console.log(uuidv4());

这里是使用 Math.random 的更快版本,使用几乎相同的原则:

函数 uuidv4() { return '00-0-4-1-000'.replace(/[^-]/g, s => ((Math.random() + ~~s) * 0x10000 >> s).toString(16).padStart(4, '0') ); } console.log(uuidv4());

只是另一个更可读的变量,只有两个突变。

function uuid4()
{
  function hex (s, b)
  {
    return s +
      (b >>> 4   ).toString (16) +  // high nibble
      (b & 0b1111).toString (16);   // low nibble
  }

  let r = crypto.getRandomValues (new Uint8Array (16));

  r[6] = r[6] >>> 4 | 0b01000000; // Set type 4: 0100
  r[8] = r[8] >>> 3 | 0b10000000; // Set variant: 100

  return r.slice ( 0,  4).reduce (hex, '' ) +
         r.slice ( 4,  6).reduce (hex, '-') +
         r.slice ( 6,  8).reduce (hex, '-') +
         r.slice ( 8, 10).reduce (hex, '-') +
         r.slice (10, 16).reduce (hex, '-');
}

ES6 样品

const guid=()=> {
  const s4=()=> Math.floor((1 + Math.random()) * 0x10000).toString(16).substring(1);     
  return `${s4() + s4()}-${s4()}-${s4()}-${s4()}-${s4() + s4() + s4()}`;
}